Mr McCandlish, a former chairman of the Mid Atholl, Grandtully and Strathtay Community Council, said improvements would be expensive.

He told BBC Scotland: "I think one of the major problems is the switch from dual to single and back again.

"If you look at the accidents it is quite evident that that has been a factor."

Mr McCandlish said local drivers knew when and where it was safe to overtake but tourists and other visitors did not have the same knowledge.

A9 fact file

The A9 is Scotland's longest road stretching for 273 miles (about 439km) between Scrabster and Falkirk

In 2005, the Scottish government said it would cost an estimated £600m to fully upgrade the road

A new overtaking lane at Moy, near Inverness, has been closed since 19 November following safety concerns

He added: "Yes, you are going to have to throw money at it but I would suggest it is probably more relevant than Edinburgh's trams."

Conservative MSP Murdo Fraser, who led a debate on the issue at Holyrood, said: "The A9 is officially Scotland's most dangerous road, with the highest fatality rate of any road in Scotland.

"I fully accept that dualling the A9 will not end accidents on the road but it is clear that dualling this road will greatly reduce the number of accidents and save lives.

"The major problems with the A9 between Perth and Inverness are the long and dangerous stretches of single carriageway and the fact that the road continually switches between single and dual carriageway."

Speaking during the debate, Transport Minister Keith Brown said the A9 had seen £50m of investment since 2007, with further investment taking place.

"We have chosen to commit to the A9 phased dualling - that's been demonstrated by the work we've taken so far, said the minister, adding: "Instead, the commitment given by the Conservatives is to prioritise trams in Edinburgh and that speaks volumes."

Mr Brown's comments prompted Mr Fraser to shout, "he's not fit to be a minister", which earned the Tory a rebuke from Holyrood's deputy presiding officer.

No funds

Transform Scotland director Colin Howden said: "Given that the government doesn't have the funds to pay for the proposed second Forth road bridge, there's certainly no money available to dual the A9.

"The best short-term solution would be to invest in average speed cameras along the length of the A9 as this would be the quickest way to reduce accidents and save lives.

"We already know that average speed cameras on the A77 have significantly cut deaths and serious injuries on that road."

Dualling the A9 road from Inverness to Perth could generate almost £1bn for the Highlands and Islands economy, according to a report commissioned by Highlands and Islands Enterprise (HIE) and transport campaign group Hitrans in 2007.

The A9 Perth to Inverness Economic Appraisal Study estimated journey times could be cut by 22 minutes.

It predicted that this would led to 724 jobs being created in the short-term rising to 4,500 over 30 years.